function bom(blob, opts) {
  if (typeof opts === 'undefined') opts = {
    autoBom: false
  }; else if (typeof opts !== 'object') {
    console.warn('Deprecated: Expected third argument to be a object');
    opts = {
      autoBom: !opts
    };
  } // prepend BOM for UTF-8 XML and text/* types (including HTML)
  // note: your browser will automatically convert UTF-16 U+FEFF to EF BB BF

  if (opts.autoBom && /^\s*(?:text\/\S*|application\/xml|\S*\/\S*\+xml)\s*;.*charset\s*=\s*utf-8/i.test(blob.type)) {
    return new Blob([String.fromCharCode(0xFEFF), blob], {
      type: blob.type
    });
  }

  return blob;
}

function download(url, name, opts) {
  var xhr = new XMLHttpRequest();
  xhr.open('GET', url);
  xhr.responseType = 'blob';

  xhr.onload = function () {
    saveAs(xhr.response, name, opts);
  };

  xhr.onerror = function () {
    console.error('could not download file');
  };

  xhr.send();
}

function corsEnabled(url) {
  var xhr = new XMLHttpRequest(); // use sync to avoid popup blocker

  xhr.open('HEAD', url, false);

  try {
    xhr.send();
  } catch (e) { }

  return xhr.status >= 200 && xhr.status <= 299;
} // `a.click()` doesn't work for all browsers (#465)


function click(node) {
  try {
    node.dispatchEvent(new MouseEvent('click'));
  } catch (e) {
    var evt = document.createEvent('MouseEvents');
    evt.initMouseEvent('click', true, true, window, 0, 0, 0, 80, 20, false, false, false, false, 0, null);
    node.dispatchEvent(evt);
  }
} // Detect WebView inside a native macOS app by ruling out all browsers
// We just need to check for 'Safari' because all other browsers (besides Firefox) include that too
// https://www.whatismybrowser.com/guides/the-latest-user-agent/macos


var isMacOSWebView = _global.navigator && /Macintosh/.test(navigator.userAgent) && /AppleWebKit/.test(navigator.userAgent) && !/Safari/.test(navigator.userAgent);
var saveAs = _global.saveAs || ( // probably in some web worker
  typeof window !== 'object' || window !== _global ? function saveAs() { }
    /* noop */
    // Use download attribute first if possible (#193 Lumia mobile) unless this is a macOS WebView
    : 'download' in HTMLAnchorElement.prototype && !isMacOSWebView ? function saveAs(blob, name, opts) {
      var URL = _global.URL || _global.webkitURL;
      var a = document.createElement('a');
      name = name || blob.name || 'download';
      a.download = name;
      a.rel = 'noopener'; // tabnabbing
      // TODO: detect chrome extensions & packaged apps
      // a.target = '_blank'

      if (typeof blob === 'string') {
        // Support regular links
        a.href = blob;

        if (a.origin !== location.origin) {
          corsEnabled(a.href) ? download(blob, name, opts) : click(a, a.target = '_blank');
        } else {
          click(a);
        }
      } else {
        // Support blobs
        a.href = URL.createObjectURL(blob);
        setTimeout(function () {
          URL.revokeObjectURL(a.href);
        }, 4E4); // 40s

        setTimeout(function () {
          click(a);
        }, 0);
      }
    } // Use msSaveOrOpenBlob as a second approach
      : 'msSaveOrOpenBlob' in navigator ? function saveAs(blob, name, opts) {
        name = name || blob.name || 'download';

        if (typeof blob === 'string') {
          if (corsEnabled(blob)) {
            download(blob, name, opts);
          } else {
            var a = document.createElement('a');
            a.href = blob;
            a.target = '_blank';
            setTimeout(function () {
              click(a);
            });
          }
        } else {
          navigator.msSaveOrOpenBlob(bom(blob, opts), name);
        }
      } // Fallback to using FileReader and a popup
        : function saveAs(blob, name, opts, popup) {
          // Open a popup immediately do go around popup blocker
          // Mostly only available on user interaction and the fileReader is async so...
          popup = popup || open('', '_blank');

          if (popup) {
            popup.document.title = popup.document.body.innerText = 'downloading...';
          }

          if (typeof blob === 'string') return download(blob, name, opts);
          var force = blob.type === 'application/octet-stream';

          var isSafari = /constructor/i.test(_global.HTMLElement) || _global.safari;

          var isChromeIOS = /CriOS\/[\d]+/.test(navigator.userAgent);

          if ((isChromeIOS || force && isSafari || isMacOSWebView) && typeof FileReader !== 'undefined') {
            // Safari doesn't allow downloading of blob URLs
            var reader = new FileReader();

            reader.onloadend = function () {
              var url = reader.result;
              url = isChromeIOS ? url : url.replace(/^data:[^;]*;/, 'data:attachment/file;');
              if (popup) popup.location.href = url; else location = url;
              popup = null; // reverse-tabnabbing #460
            };

            reader.readAsDataURL(blob);
          } else {
            var URL = _global.URL || _global.webkitURL;
            var url = URL.createObjectURL(blob);
            if (popup) popup.location = url; else location.href = url;
            popup = null; // reverse-tabnabbing #460

            setTimeout(function () {
              URL.revokeObjectURL(url);
            }, 4E4); // 40s
          }
        })